Fix macro placement in pg_config.h.in

Commit 274bbce accidentally placed the pg_config.h.in
for SSL_CTX_set_num_tickets on the wrong line wrt where autoheader
places it.  Fix by re-arranging and backpatch to the same level as
the original commit.

Reported-by: Marina Polyakova <m.polyakova@postgrespro.ru>
Discussion: https://postgr.es/m/48cebe8c3eaf308bae253b1dbf4e4a75@postgrespro.ru
Backpatch-through: v12

Author: danielgustafsson

src/include/pg_config.h.in

@@ -384,6 +384,9 @@
 /* Define to 1 if you have the `SSL_CTX_set_cert_cb' function. */
 #undef HAVE_SSL_CTX_SET_CERT_CB
 
+/* Define to 1 if you have the `SSL_CTX_set_num_tickets' function. */
+#undef HAVE_SSL_CTX_SET_NUM_TICKETS
+
 /* Define to 1 if stdbool.h conforms to C99. */
 #undef HAVE_STDBOOL_H
 
@@ -510,9 +513,6 @@
 /* Define to 1 if you have the `X509_get_signature_info' function. */
 #undef HAVE_X509_GET_SIGNATURE_INFO
 
-/* Define to 1 if you have the `SSL_CTX_set_num_tickets' function. */
-#undef HAVE_SSL_CTX_SET_NUM_TICKETS
-
 /* Define to 1 if the assembler supports X86_64's POPCNTQ instruction. */
 #undef HAVE_X86_64_POPCNTQ